Americans are accustomed to tipping for a wide array of services. We understand that our gratuity makes up an important percentage of the wages earned by many different types of laborers: massage therapists, Uber drivers, hair stylists, tour guides, room service providers, valets — the list goes on. Much of the time, we don’t just add a tip because we’re adhering to a cultural norm but rather because we genuinely want to acknowledge good service and show gratitude.

The growing popularity of digital payment terminals has increased the number of opportunities for customers to leave a tip. The New York City bodega that I patronize several times per week is a perfect example. The checkout terminal gives me the option to tip 15, 20, or 25 percent every time I make a purchase, regardless of whether I order a sandwich or I’m paying for basic sundries that don’t require any preparation. The same goes for the coffee shop that brews my favorite blend. The digital terminal spins around, and presto: 15 percent for the macchiato and the chocolate rugelach.

That’s a generally good thing. I’m OK with showing more appreciation in more places for more things. But if the mouth of the “American tip jar” is truly in the process of opening a bit wider, maybe it’s time for us to reconsider who has been left out in the cold. Who else deserves to have their hearts and hands warmed up by an occasional flicker of financial generosity? What about dental hygienists? What about nurses?

Why have these hard-working professionals been excluded from the unfolding transformation? No offense to hotel bellmen, bartenders, and servers — they should continue to receive recompense — but I must confess that I feel a stronger sense of gratitude toward my dental hygienist, who spends a full hour scraping away tartar from the base of my teeth. Why shouldn’t Larry David and I be able to tip our hygienists if we so choose? If the lines of proper tipping etiquette are being redrawn, it’s time to include dental technicians on the new map.

Millions of Americans don’t have dental insurance and pay out-of-pocket for a routine cleaning. Considering the fact that the cleaning itself can cost $150 to $200, adding a tip becomes an expensive proposition. With that being said, massage therapists routinely receive tips after they work out the knots in our backs, even though the establishment charges us for the basic service. It is also not uncommon for women to pay a hair salon upwards of $100 for a “cut and coloring” and then add a tip on top of that basic premium.

Would tipping hygienists open a Pandora’s box and cause an avalanche of open palms for health care-related services? And where should we draw the line? Should occupational therapists receive a gratuity for helping people regain their dignity and independence? What about vestibular therapists — is restoring proper balance worthy of a tip? How about nutritionists? And last but not least, what about nurses?

When the day comes that I require hospital care — and if I still have my wits about me — I would relish an opportunity to show some extra gratitude to the nurses who tend to the involuntary whims of my body and my corporal decay. I realize that not everyone who gets sick has the means to express gratitude with a monetary “thank you,” but that doesn’t mean it shouldn’t be presented as an option. Perhaps, hospital protocol might allow patients to “add a tip” after discharge and require that the source of the gratuity remain anonymous.

The provision of health care carries an inherent expectation that every patient receives the same level of care regardless of their insurance or ability to pay. Medical doctors, dentists, and podiatrists receive ample reimbursement for their labor. If these highly compensated professionals even flirted with the idea of accepting additional gratuity, it would tarnish the sanctity of the bond between physician and patient, cause distrust and diminish the nobility of the profession.

I’m not sure the same can be said for dental hygienists and nurses. The honest hard work that they perform in the trenches every day should not just be recognized, but it should finally be rewarded with an opportunity for better compensation.

Eric Dessner is an ophthalmologist in Brooklyn, NY, and can be reached on Twitter @eric_dessner. He is founder and CEO, Medmic.